Your force given the time frame would be representative of a force reformed out of escaped/retreating forces of around BN Plus. Artillery is handed down from Division to Regiment at this time of war; Regt would decide what a Bn would get in support, likely depending on mission and availability. I would say your artillery would be very heavy for BN core forces, as Imp has mentioned. However, as attached from higher in your support forces, it would not be out of line if the Bn is part of the main push, advancing or assaulting.
However being an adhoc force cobbled together from odds and sods, who's to say what artillery you managed to pick up. Personally I wouldn't dump the artillery at least for a year when your unit would be a properly formed line unit again.
As the war progresses, this support will become more liberal to say the least: I'm sure the Russians must have a saying which says "You can never have too much Artillery!!" or something to that effect! LOL
This gives you an ideal of where the Batteries come from generally.
http://rkkaww2.armchairgeneral.com/s.../rfldivart.gif
This for later in the war, but has the breakdowns of the attached Artillery Unit, plus many other interesting details.
http://www.fireandfury.com/orbats/russianob.pdf
This is for early in the war, but doesn't give details of the guns being assigned by higher.
http://www.fireandfury.com/orbats/blitzewruss.pdf
Hope these are of help. Bottom-line for early in the Ostfront, Some Units were being thrown together adhoc, as the Russians reeled back. I'm playing a PBEM as the Russians in just this situation and roughly the same size unit, although I started with fewer tanks and old ones at that. My force has fair share of Artillery as well only because I'm considering it a Fire Brigade.
Bob out